• Fisheries and Aquatic Sciences
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• 제18권4호
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• pp.387-393
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• 2015

Biotyping of Vibrio vulnificus strains isolated from marine environments along the south coast of Korea showed that the majority of the isolates (94.7%) belonged to biotype 1 and the remaining isolates (5.3%) belonged to biotype 2. Analysis of 16S rRNA V. vulnificus strains isolated from marine environments using a multiplex polymerase chain reaction (PCR) revealed that 78.7% were type A and 21.3% were type B. Random amplified polymorphic DNA (RAPD) was used to analyze the genomic differences in V. vulnificus among the biotype 2 strains isolated from marine environments (newly isolated strains group) and reference strains obtained from infected eels (reference strains group). The two groups had distinctly different profiles of the amplicons produced from RAPD. Additionally, biochemical comparison of these strains revealed that all four strains isolated from marine environments differed from the strains isolated from eels in their ability to promote D-mannitol fermentation. Two (NH 1 and NH 2) out of four isolates of biotype 2 from marine environments showed pathogenicity in eels Anguilla japonica in a challenge test. These isolates did not agglutinate with antisera against V. vulnificus NCIMB 2137 (serovar E), ATCC 27562 (non-serovar E), and ATCC 33816 (atypical serovar E).

• 한국동물위생학회지
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• 제32권2호
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• pp.139-146
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• 2009

Bovine brucellosis is a zoonosis, long incubation period and chronic infectious disease, usually caused by Brucella abortus. This study was carried out to investigate the biotyping and biochemical characterization of B. abortus isolated from 208 farm 871 korean cattle and holstein diagnosed brucellosis by serological positive in Gyeongbuk province during the period from 2002 to 2006. B. abortus was isolated from 124 (14.2%) of 871 cattle, and isolated 110 (13.4%) of 820 Korean cattle and 14 (27.5%) of 51 holstein in breed. The uterus of korean cattle was isolated in 8 (17.8%) of 45 cattle and supramammary lymph none of holstein was isolated 11 (68.8%) of 16 cattle. 101 (12.5%) of 810 serological positive blood samples were isolated B. abortus. The isolation rate of B. abortus was correlated with antibody titers. The biochemical characterization of isolates was non-hemolytic, production of H$_2$S, oxidase-positive, catalase-positive, hydrolyzation of urea and growth of basic fuchsin dye medium. As a result, all of isolates was identified B. abortus bv 1. 124 isolates were susceptible to ampicillin, lincospectin, amikacin, gentamicin, kanamycin, neomycin, streptomycin, tetracycline, ciprofloxacin, norfloxacin and enrofloxacin.

• Earthquakes and Structures
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• 제13권6호
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• pp.561-572
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• 2017

Seismic base isolation has been accepted as one of the most popular design procedures to protect important structures against earthquakes. However, due to lack of information and experimental data the application of base isolation is quite limited to nuclear power plant (NPP) industry. Moreover, the effects of inelastic behavior of soil beneath base-isolated NPP have raised questions to the effectiveness of isolation device. This study applies the wavelet analysis to investigate the effects of soil-structure interaction (SSI) on the seismic response of a base-isolated NPP structure. To evaluate the SSI effects, the NPP structure is modelled as a lumped mass stick model and combined with a soil model using the concept of cone models. The lead rubber bearing (LRB) base isolator is used to adopt the base isolation system. The shear wave velocity of soil is varied to reflect the real rock site conditions of structure. The comparison between seismic performance of isolated structure and non-isolated structure has drawn. The results show that the wavelet analysis proves to be an efficient tool to evaluate the SSI effects on the seismic response of base-isolated structure and the seismic performance of base-isolated NPP is not sensitive to the effects in this case.

• 한국지진공학회논문집
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• 제28권1호
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• pp.1-10
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• 2024

For important structures such as nuclear power plants, In-Structure Response Spectrum (ISRS) analysis is essential because it evaluates the safety of equipment and components installed in the structure. Because most structures are asymmetric, the response can be affected by eccentricity. In the case of seismically isolated structures, this effect can be greater due to the difference between the center of mass of the structure and the center of rigidity of the isolator layer. Therefore, eccentricity effects must be considered when designing or evaluating the ISRS of seismically isolated structures. This study investigated the change of the ISRS of an isolated structure by assuming accidental eccentricity. The variables that affect the ISRS of the isolated structure were analyzed to see what additional impact they had due to eccentricity. The ISRS of the seismically isolated structure with eccentricity was amplified more than when there was non-eccentricity, and it was boosted more significantly in specific period ranges depending on the isolator's initial stiffness and seismic intensity. Finally, whether the displacement requirement of isolators can be applied to the variation of the ISRS due to eccentricity in the design code was also examined.

• 한국수산과학회지
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• 제30권4호
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• pp.550-555
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• 1997

수온 $25^{\circ}C$ 부근의 $7\~8$월에 걸쳐 해수로부터 V. cholerae non-O1을 분리하여 분리된 균주 중 용혈활성이 가장 확실한 균주를 선정하여 V. cholerae non-O1 FM-3으로 명명하고 이 균의 생육인자와 항생제에 대한 감수성을 조사하였다. 1. 분리균주 (V. cholerae non-O1 FM-3)는 Gram 음성간균으로 운동성이 있으며, Voges-Proskauer test 양성으로 galactose와 sucrose를 분해하고 arabinose, lactose, salicin을 분해하지 못하며, CAMP test 양성으로서 표준균주와 동일한 생화학적 특성을 나타내었다. 2. $4\~50^{\circ}C$의 범위에서 생육에 대한 영향을 조사한 결과, 표준균주와 분리균주 모두 $4^{\circ}C$와 $50^{\circ}C$에서는 생육이 불가능하였으나 $15\~45^{\circ}C$의 온도범위에서는 생육하였으며 두 균주의 증식 최적조건은 $37^{\circ}C$로 나타났다. 특히 생육온도 범위내에서 분리균주는 표준균주보다 높은 증식율을 나타내었다. 3. $0\~5.0\%$의 식염농도에서 생육에 대한 영향을 조사한 결과, 표준균주와 분리균주 모두 $0\~1.0\%$식염농도에서 증식율이 가장 높게 나타났으며, 표준균주보다 분리균주의 증식속도가 약간 빠른 경향을 나타내었다. $3\%$식염농도에서도 표준균주에 비해 분리균주가 증식율이 높았다. 한편, $5\%$의 식염농도에서 표준균주는 생육이 불가능하였으나 분리균주는 미약하나마 증식하는 것으로 나타났다. 4. $pH\;5.0\~10.0$의 범위에서 생육에 대한 영향을 조사한 결과, $pH7\~9$의 범위에서 표준균주와 분리균주는 모두 잘 증식하였으며, 특히 pH8.5에서 가장 높은 증식율을 나타내었다. 한편 pH6.0과 pH10.0에서는 증식율이 감소하였고, pH5.0에서는 전혀 증식하지 않았다. 5. 표준균주와 분리균주는 모두 vancomycin, oxacillin, colistin, polymyxin B, sulfadiazine 등의 항생제에 대해서는 내성을 나타내었고, 그 외 다른 항생제에 대해서는 민감한 것으로 나타났다.

• 농업과학연구
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• 제39권3호
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• pp.387-393
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• 2012

In the present study, ${\beta}$-glucanase-assisted extraction of starch from glutinous barley(Hinchal ssalbory) was investigated. ${\beta}$-glucanase was added to a coarse starch suspension obtained after wet milling in the starch extraction process. It was found that in the isolated starch with enzyme treatment, protein content was lower by 0.03%, compared to that with non-enzyme treatment. More importantly it was observed that the extraction yield of starch from enzyme treatment was found to be about 12% higher than the one from non-enzyme treatment (enzyme treated: 90.56%, non-enzyme treated: 78.46%). In order to elucidate this finding, the mass-balance determination of starch in each extraction step was carried out and found that the enzyme treatment might influence on the insoluble residues(R3 and R4 fractions) to hydrolyze ${\beta}$-glucan and other materials (e.g., mucilages etc.), thereby facilitated the separation of starch from it and a next filtration process. With a phase-contrast microscope it was observed that the isolated starch with enzyme treatment contained small starch granules more than the one with non-enzyme treatment and this might result in higher extraction yield observed with the former. In order to confirm this hypothesis, further experiments would be necessary.

• The Korean Journal of Physiology and Pharmacology
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• 제13권6호
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• pp.455-460
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• 2009

Glutamate-induced cobalt uptake reveals that non-NMDA glutamate receptors (GluRs) are present in rat taste bud cells. Previous studies involving glutamate induced cobalt staining suggest this uptake mainly occurs via kainate type GluRs. It is not known which of the 4 types of taste bud cells express subunits of kainate GluR. Circumvallate and foliate papillae of Sprague-Dawley rats (45~60 days old) were used to search for the mRNAs of subunits of non-NMDA GluRs using RT-PCR with specific primers for GluR1-7, KA1 and KA2. We also performed RT-PCR for GluR5, KA1, $PLC\beta2$, and NCAM/SNAP 25 in isolated single cells from taste buds. Taste epithelium, including circumvallate or foliate papilla, express mRNAs of GluR5 and KA1. However, non-taste tongue epithelium expresses no subunits of non-NMDA GluRs. Isolated single cell RT-PCR reveals that the mRNAs of GluR5 and KA1 are preferentially expressed in Type II and Type III cells over Type I cells.

• Structural Engineering and Mechanics
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• 제75권1호
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• pp.33-47
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• 2020

In this paper the dynamic behavior of an isolated building subjected to idealized near-fault pulses is investigated. The building is represented with a simple 2-DOF model. Both linear and non-linear behavior of the isolation system is considered. Using dimensional analysis, in conjunction with closed form mathematical idealized pulses, appropriate dimensionless parameters are defined and self-similar curves are plotted on dimensionless graphs, based on which various conclusions are reached. In the linear case, the role of viscous damping is examined in detail and the existence of an optimum value of damping along with its significant variation with the number of half-cycles is shown. In the nonlinear case, where the behavior of the building depends on the amplitude of the excitation, the benefits of dimensional analysis are evident since the influence of the dimensionless 𝚷-terms is easily examined. Special consideration is given to the normalized strength of the non-linear isolation system that appears to play a complex role which greatly affects the response of the 2-DOF. In the last part of the paper, a comparison of the responses to idealized pulses between a linear fixed-base SDOF and the respective isolated 2-DOF with both linear and non-linear damping is conducted and it is shown that, under certain values of the superstructure and isolation system characteristics, the use of an isolation system can amplify both the normalized acceleration and displacement of the superstructure.

• Nuclear Engineering and Technology
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• 제52권1호
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• pp.192-205
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• 2020

Seismic design practices and seismic response analyses of civil structures and nuclear power plants (NPPs) have conventionally used the peak ground acceleration (PGA) or spectral acceleration (S_a) as an intensity measure (IM) of an earthquake. However, there are many other earthquake IMs that were proposed by various researchers. The aim of this study is to investigate the correlation between seismic responses of NPP components and 23 earthquake IMs and identify the best IMs for correlating with damage of NPP structures. Particularly, low- and high-frequency ground motion records are separately accounted in correlation analyses. An advanced power reactor NPP in Korea, APR1400, is selected for numerical analyses where containment and auxiliary buildings are modeled using SAP2000. Floor displacements and accelerations are monitored for the non- and base-isolated NPP structures while shear deformations of the base isolator are additionally monitored for the base-isolated NPP. A series of Pearson's correlation coefficients are calculated to recognize the correlation between each of the 23 earthquake IMs and responses of NPP structures. The numerical results demonstrate that there is a significant difference in the correlation between earthquake IMs and seismic responses of non-isolated NPP structures considering low- and high-frequency ground motion groups. Meanwhile, a trivial discrepancy of the correlation is observed in the case of the base-isolated NPP subjected to the two groups of ground motions. Moreover, a selection of PGA or S_a for seismic response analyses of NPP structures in the high-frequency seismic regions may not be the best option. Additionally, a set of fragility curves are thereafter developed for the base-isolated NPP based on the shear deformation of lead rubber bearing (LRB) with respect to the strongly correlated IMs. The results reveal that the probability of damage to the structure is higher for low-frequency earthquakes compared with that of high-frequency ground motions.

• Earthquakes and Structures
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• 제13권4호
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• pp.353-363
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• 2017

The present study considers a multi-span continuous bridge, isolated by lead rubber bearing (LRB). Dynamic soilstructure interaction (SSI) is modelled with the help of a simplified, sway-rocking model for different types of soil. It is well understood from the literature that SSI influences the structural responses and the isolator performance. However, the abovementioned effect of SSI also depends on the earthquake ground motion properties. It is very important to understand how the interaction between soil and structure varies with the earthquake ground motion characteristics but, as far as the knowledge of the authors go, no study has been carried out to investigate this effect. Therefore, the objectives of the present study are to investigate the influence of earthquake ground motion characteristics on: (a) the responses of a multi span bridge (isolated and non-isolated), (b) the performance of the isolator and, most importantly, (c) the soil-structure interaction. Statistical analyses are conducted by considering 14 earthquakes which are selected in such a way that they can be categorized into three frequency content groups according to their peak ground acceleration to peak ground velocity (PGA/PGV) ratio. Lumped mass model of the bridge is developed and time history analyses are carried out by solving the governing equations of motion in the state space form. The performance of the isolator is studied by comparing the responses of the bridge with those of the corresponding uncontrolled bridge (i.e., non-isolated bridge). On studying the effect of earthquake motions, it is observed that the earthquake ground motion characteristics affect the interaction between soil and structure in such a way that the responses decrease with increase in frequency content of the earthquake for all the types of soil considered. The reverse phenomenon is observed in case of the isolator performance where the control efficiencies increase with frequency content of earthquake.